Swagless turnbuckle assembly

ABSTRACT

A cable gripping apparatus comprising a plurality of jaw members, each jaw member being tapered on an outer surface thereof from a larger first end to a smaller second end, said plurality of jaw members being configured to receive and grip a cable therebetween. A cylindrical collar having external threads and a tapered internal bore is receivable of the tapered jaw members in the tapered internal bore. A cylindrical turnbuckle body having a threaded bore is receivable of the threaded cylindrical collar entirely within the turnbuckle bore. The cylindrical collar, plurality of jaw members, and cable gripped therewithin define collectively a collar sub-assembly receivable within the turnbuckle bore. When the turnbuckle body is rotated, the collar sub-assembly is moved axially within the threaded bore of the turnbuckle body, thus changing the tension in the cable.

RELATIONSHIP TO OTHER PATENTS AND APPLICATIONS

The present application draws priority from U.S. Provisional PatentApplication No. 62/355,998, filed Jun. 29, 2016, which is incorporatedby reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to an improved cable grippingapparatus for use in attaching cables between posts or the like; moreparticularly, to such an apparatus for tensioning such an attachedcable; and most particularly, to such an apparatus operative to attachand tension a cable between two points on a structure without requiringuse of a swaging ferrule and swaging tool, while allowing the installerto make easy adjustments to the length and tension of the cable.

BACKGROUND OF THE INVENTION

A conventional cable railing system comprises a plurality of verticalposts with cables attached to and extending between the posts.Typically, it is desirable to keep the cables under tension, and theattachment hardware is designed such that tension in the cables may beadjusted at, the time of installation or thereafter as may be needed.

A typical turnbuckle system comprises a first male threaded fittingswaged onto the end of a cable of appropriate length attached to a firstpost and a second male threaded fitting attached to a second post. Thefirst and second threads are opposite threaded (left hand and right handthreads). A turnbuckle body having left and right hand internal femalethreads is installed onto the first and second threaded fittings, whichturnbuckle body by being rotated serves to draw on the cable between theturnbuckle body and the first post, thereby tensioning the cable.

Such existing devices are necessarily complex, expensive, and difficultto install in the field, requiring a first swaging step of the cable(which may also require both a swaging ferrule and a swaging tool)followed by assembly into a turnbuckle for the second step of tensioningof the secured cable as may be desired.

It is known to avoid the first swaging step in devices for securing theend of a cable, but such devices typically relinquish the turnbucklefunction, as shown in the following examples.

US Patent Application No. 2014/0230599 by Chen, filed Apr. 25, 2014,discloses a cable connection device comprising an outer barrel, an innerconnecting member, and a tube, wherein an outer thread is arranged atone end of the tube, and a cone portion is arranged inside the end ofthe tube having the outer thread tapered inwardly; an inner threadarranged at one end of the outer barrel is screwed with the outer threadof the tube, and a flange is arranged inside the end of the outer barrelaway from the inner thread; and two flexible latches of the innerconnecting member are disposed inside the cone portion, and an outerconvex ring arranged between two ends of the inner connecting member isagainst the flange adjacent to the inner thread. The flexible latchesare compressed by the cone portion to fasten one end of a cable passedthrough the tube.

A shortcoming of this apparatus is that it makes no provision forfurther tensioning of the cable after the cable has been secured intothe tube because the outer thread of the tube is free at only one endand is captive to the tube at its other end.

US Patent Application Publication No. 2011/0084180 by Toimil et al.,filed Oct. 13, 2010, discloses an interchangeable, self-locking, cablegripping and adaptive anchoring apparatus comprising a grippingcomponent and adaptor component. The adaptor component comprises areceiving side for a fitting or anchoring device, and a connector sideto engage with a cable or the like. The gripping component comprises ahousing having a cable receiving end and dispatching end. The housingholds cable gripping elements comprising a spring, spacer, and two jaws,within a tapering bore of the housing. At the dispatching end, thehousing comprises an internal bore for engaging around the connectorside of the adaptor component. The gripping component is spring-loadedand self-locking for securing a cable. The pressure of the adaptorcomponent connector side against the spring, spacer, and jaws, locks theinserted cable in place to allow the cable to move in only onedirection. The adaptor component engages flush against the housing tocontain the housing components.

A shortcoming of this apparatus is that once the cable is gripped withinthe housing and the adaptor component is inserted fully into thehousing, there is no provision for moving the cable further axiallywithin the anchoring apparatus as is required to tension the cable. Thecable may be further tensioned only by rotating the entire grippingcomponent assembly, including the cable, on the fitting or anchoringdevice threaded into the receiving end of the adaptor component.

Therefore, there exists a need to provide a simple, easily assembled,cable gripping and tensioning apparatus comprising an integralturnbuckle assembly wherein, a cable is gripped by elements within theturnbuckle body itself and may be advanced axially within the turnbucklebody as may be desired in a separate step after the cable is gripped,which apparatus can be used to adjust the tension and length of thecable easily by the installer in the field.

SUMMARY OF THE INVENTION

A cable gripping and tensioning apparatus is provided which includes aplurality of jaw members, preferably two. The jaw members taper from alarger first end to a smaller second end. The plurality of jaw membersare configured to receive the cable therebetween in an internal boreformed jointly or collectively by the plurality of jaw members, whichbore may include threads or other features to assist in gripping thecable.

A cylindrical collar free at both ends is provided having externalthreads and having a tapered internal bore adapted to receive theplurality of tapered jaw members. When the cable is inserted into theinternal bore of the jaw members, and the jaw members are inserted intothe tapered internal bore of the cylindrical collar, the jaws are urgedagainst the cable to hold it in place and the jaws are axiallyimmobilized within the tapered internal bore of the threaded cylindricalcollar.

The cable may be inserted into the jaw members either before or afterthe jaw members are entered into the tapered internal bore of thecylindrical collar.

A turnbuckle body has a threaded bore adapted for receiving the externalthreads of the collar entirely within the threaded bore such that whenthe turnbuckle body is rotated, the collar moves axially within thethreaded bore of the turnbuckle body, taking with it the plurality ofjaws and the gripped cable, and thus causing adjustment of tension inthe cable.

In one embodiment, the cable gripping apparatus includes ridges in thetapered internal bore of the collar to engage a surface of at least oneof the jaw members.

In another embodiment, the cable gripping apparatus includes a pawl inthe collar adapted to engage a portion of at least one of the jawmembers to prevent axial disengagement of the jaw members from thetapered internal bore of the collar.

In yet another embodiment, the jaw members of the cable grippingapparatus include a groove proximate the larger first end and furtherinclude an O-ring adapted to be received in the groove. The innerdiameter of the collar also may include a mating groove to also receivethe O-ring.

DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of theinvention, as well as presently preferred embodiments thereof, willbecome more apparent from a reading of the following description inconnection with the accompanying drawings in which:

FIG. 1 is an exploded perspective view of a first embodiment inaccordance with the present invention;

FIG. 2 is a longitudinal cross-sectional view of a portion of theembodiment shown in FIG. 1, showing a cable inserted into the jawmembers, and the jaw members inserted into the collar;

FIG. 3 is a detailed cross-sectional view taken from Circle 3 in FIG. 2,showing the relationship among the O-ring, collar, and jaw members;

FIG. 4 is an assembled perspective view of the present invention,including a sealing cap not previously shown;

FIG. 5 is a longitudinal cross-sectional view of the embodiment shown inFIG. 4;

FIG. 6 is a side elevational view of a portion of a second embodiment inaccordance with the present invention;

FIG. 7 is a longitudinal cross-sectional view of the second embodimenttaken along the line A-A in FIG. 6;

FIG. 8 is a detailed cross-sectional view of a portion of the secondembodiment shown in FIG. 7;

FIG. 9 is a side elevational view of a portion of a third embodiment inaccordance with the present invention;

FIG. 10 is a longitudinal cross-sectional view of the third embodimenttaken along the line A-A in FIG. 9;

FIG. 11 is a detailed cross-sectional view of a portion of the thirdembodiment shown in FIG. 10;

FIG. 12 is a side elevational view of a portion of a fourth embodimentin accordance with the present invention;

FIG. 13 is a longitudinal cross-sectional view of the fourth embodimentshown in FIG. 12; and

FIG. 14 is a detailed cross-sectional view of a portion of the fourthembodiment shown in FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 through 14 illustrate various embodiments of the presentinvention in which a novel attachment and tensioning apparatus 10 foruse with, e.g., a cable railing system, is shown.

Referring now to FIGS. 1 through 5, a first embodiment 10 in accordancewith the present invention comprises a plurality (two shown) of jawmembers 12,14 having a larger first end 16 and a smaller second end 18.Optionally, jaw members 12,14 include a circumferential groove 20 forreceiving an optional O-ring 22. O-ring 22 serves to hold jaw members12,14 in close proximity to each other for ease of installation of thejaw members into tapered bore 32 of cylindrical collar 30. Jaw members12,14 cooperate to define an internal bore 24 with optional features 26therein to assist in gripping cable 28. Cylindrical collar 30 includesexternal male threads 34. A turnbuckle body 40 is provided with internalfemale threads 42 in bore 44 that match threads 34. Collar 30 isthreaded into turnbuckle body 40 and is adapted to be receivedcompletely inside of turnbuckle body 40.

In a first method of operation, optional O-ring 22 is placed in groove20 of jaw members 12,14. Cable 28 is placed into collar bore 32. Jawmembers 12,14 are placed on cable 28 and inserted into collar bore 32,defining a collar sub-assembly 31 that itself is threaded into bore 44of turnbuckle body 40.

In a second method of operation, jaw members 12,14 are inserted intocollar bore 32, and collar 30 is threaded into turnbuckle body 40. Theapparatus is now ready to receive an end of cable 28.

The first and second methods of operation arrive at the same statuswherein the cable is being gripped by the jaw members within the collarwithin the turnbuckle body. To adjust the length and tension of cable28, turnbuckle body 40 is rotated either clockwise or counterclockwisesuch that collar sub-assembly 31 is moved axially within turnbuckle body40. Collar sub-assembly 31 is held completely within turnbuckle body 40.

Optionally, cap 50 may be installed onto cable 28 via a central aperturein the cap prior to either of the above assembly procedures and thenthreaded into turnbuckle body 40 to seal cable attachment and tensioningapparatus 10.

Referring now to FIGS. 6 through 8, in a second embodiment 231 of acollar sub-assembly in accordance with the present invention, collar 230includes internal ridges 250 that grip jaw members 12,14 to hold them inplace and prevent them from sliding axially out of collar 230 duringassembly.

Referring now to FIGS. 9 through 11, in a third embodiment 331 of acollar sub-assembly in accordance with the present invention, collar 330includes a circumferential groove 360 matable with a correspondinggroove 320 in jaw members 312,314. When jaw members 312,314 are insertedinto collar 330, O-ring 322 is seated within groove 320/360 to hold jawmembers 312,314 in place during assembly.

Referring now to FIGS. 12 through 14, in a fourth embodiment 431 of acollar sub-assembly in accordance with the present invention, collar 430includes a pawl 470 and the jaw members 412,414 include an externalridge 472. Pawl 470 engages with external ridge 472 when jaw members412,414 are inserted into collar 430 to prevent jaw members 412,414 fromsliding axially out of collar 430 during assembly.

From the foregoing description, it will be apparent that there has beenprovided an improved method and apparatus for attaching and tensioning acable. Variations and modifications of the herein described method andapparatus, in accordance with the present invention, will undoubtedlysuggest themselves to those skilled in this art. Accordingly, theforegoing description should be taken as illustrative and not in alimiting sense.

What is claimed is:
 1. A cable gripping and tensioning apparatuscomprising: a) a plurality of jaw members, each jaw member being taperedon an outer surface thereof from a larger first end to a smaller secondend, said plurality of jaw members being configured to receive and gripa cable therebetween; b) a cylindrical collar having first and secondfree ends and having external threads between said first and second freeends and a tapered internal bore therein receivable of said plurality oftapered jaw members in said tapered internal bore; and c) a turnbucklebody having a threaded bore receivable of said threaded cylindricalcollar entirely within said threaded bore, wherein tension exerted onsaid cable urges said plurality of jaw members into locking contactwithin said tapered internal bore of said cylindrical collar, whereinsaid threaded bore of said turnbuckle body is longer than said threadedcylindrical collar such that both of said first and second free ends ofsaid threaded cylindrical collar may be contained simultaneously withinsaid threaded bore of said turnbuckle body, and wherein tension in saidcable can be varied by axial movement of said collar within saidturnbuckle body at any time while said cable is secured in said collarby said jaw members.
 2. A cable gripping apparatus in accordance withclaim 1 wherein said cylindrical collar, said plurality of jaw members,and a cable gripped therewithin define collectively a collarsub-assembly receivable within said threaded turnbuckle bore, andwherein when said turnbuckle body is rotated, said collar sub-assemblyis moved axially within said threaded bore of said turnbuckle body tovary tension in said cable.
 3. A cable gripping apparatus in accordancewith claim 1 further comprising ridges in said inner bore of said collaradapted to engage said outer surface of at least one of said jawmembers.
 4. A cable gripping apparatus in accordance with claim 1wherein said plurality of jaw members cooperatively define an axial boretherewithin.
 5. A cable gripping apparatus in accordance with claim 4wherein said axial bore is provided with features to assist in grippingsaid cable.
 6. A cable gripping apparatus in accordance with claim 1further comprising at least one pawl formed in said collar and adaptedto engage a portion of at least one of said jaw members.
 7. A cablegripping apparatus in accordance with claim 1 further comprising a firstgroove formed in said plurality of jaw members proximate said larger endand including an O-ring adapted to be received in said groove.
 8. Acable gripping apparatus in accordance with claim 7 further comprising asecond groove formed in said inner diameter of said collar and adaptedto also receive said O-ring.
 9. A method for changing tension in a cabledeployed between two fixed points, comprising the steps of: a) providinga cable gripping and tensioning apparatus including a plurality of jawmembers tapered on an outer surface thereof and configured to receiveand grip a cable therebetween, a cylindrical collar having first andsecond free ends and having external threads and a tapered internal borereceivable of said tapered jaw members, and a turnbuckle body having athreaded bore receivable of said threaded cylindrical collar entirelywithin said threaded bore; b) securing a first end of said cable to oneof said fixed points; c) securing an end of said turnbuckle body to theother of said fixed points such that said turnbuckle body is axiallyrotatable; d) inserting the second and opposite end of said cableaxially into said jaw members within said turnbuckle body; and e)rotating said turnbuckle body to cause said jaw members to grip saidsecond end of said cable and said cylindrical collar to move axiallywithin said turnbuckle body, thereby changing tension in said cable.